While the SGE series masks by Mestel provide an enormous field of view at 87%, that's not of much use if your optical sensors are malfunctioning. In other words, if you use glasses, you're going to want one of these.
Designed to be snapped inside the SGE series mask without the use of any tools or worn independently (arms not included), getting a prescription set-up gas mask is as easy as purchasing one of these and having lenses made by your favorite optician. They feature ample ventilation on the side to reduce fogging.
Installation Diagram
Compatibility
The optical lens support works in the SGE 150, 400/3, and 400/3 BB full face gas masks.
Specs